Easy, go to bed 8 hours before you want to get up. I've been sleeping with ear plugs in for at least a year now, and I have black out curtains so it's always night time in my bedroom.

I've always wanted to be able to sleep with ear plugs, but I'm too worried I'd oversleep. I sleep with a mask just fine, and generally wake up after 8-8.5 hours of sleep, but there's still some hesitancy